Where is Starling City?

Does anyone know if it's on the East coast or the west coast? I'm thinking it's on the East coast based on things such as the news station's call letters begin with a "W" meaning Starling is on the east coast. However, Robert was taking the Gambit to China and Oliver thought it would only be a 3 week trip. Was Robert really going to take a boat trip from the east coast to China? How long would it take to get from either the East or West coast to china?